Selenium is important because it acts as a powerful antioxidant, helping to protect cells from damage caused by free radicals. It supports thyroid function, immune system health, and reproductive health. Selenium is important because it acts as a powerful antioxidant, helping to protect cells from damage caused by free radicals. It supports thyroid function, immune system health, and reproductive health. Health and Fitness, Health Tips, Exercises & Workout Tips, Diet & Wellness | Times of India Lifestyle